Posted by earthworm on
URL: https://www.es-forum.com/Elementary-question-please-tp4032331p4032343.html

The earplug will turn into an antenna, emitting right on top of the ear.
So ordinary headphones are of little use and possibly even worse.
You need either these airtube ones or those with a transformer halfway the wires.
However both still emit pretty close to your body.
If the phone has a good speaker and microphone and there is not a lot of noise around, it is preferable to use the speakerphone function and keep as much distance as is workable, 3 meter or 10 feet is often no problem.